diff --git a/bar/bar.c b/bar/bar.c
index 065460b..f252ca5 100644
--- a/bar/bar.c
+++ b/bar/bar.c
@@ -367,7 +367,7 @@ destroy(struct bar *bar)
 struct bar *
 bar_new(const struct bar_config *config)
 {
-    struct private *priv = malloc(sizeof(*priv));
+    struct private *priv = calloc(1, sizeof(*priv));
     priv->monitor = config->monitor != NULL ? strdup(config->monitor) : NULL;
     priv->location = config->location;
     priv->height = config->height;
@@ -379,15 +379,14 @@ bar_new(const struct bar_config *config)
     priv->border.width = config->border.width;
     priv->border.color = config->border.color;
     priv->left.mods = malloc(config->left.count * sizeof(priv->left.mods[0]));
-    priv->left.exps = malloc(config->left.count * sizeof(priv->left.exps[0]));
+    priv->left.exps = calloc(config->left.count, sizeof(priv->left.exps[0]));
     priv->center.mods = malloc(config->center.count * sizeof(priv->center.mods[0]));
-    priv->center.exps = malloc(config->center.count * sizeof(priv->center.exps[0]));
+    priv->center.exps = calloc(config->center.count, sizeof(priv->center.exps[0]));
     priv->right.mods = malloc(config->right.count * sizeof(priv->right.mods[0]));
-    priv->right.exps = malloc(config->right.count * sizeof(priv->right.exps[0]));
+    priv->right.exps = calloc(config->right.count, sizeof(priv->right.exps[0]));
     priv->left.count = config->left.count;
     priv->center.count = config->center.count;
     priv->right.count = config->right.count;
-    priv->cursor_name = NULL;
 
 #if defined(ENABLE_X11) && !defined(ENABLE_WAYLAND)
     priv->backend.data = bar_backend_xcb_new();
@@ -407,20 +406,14 @@ bar_new(const struct bar_config *config)
 #endif
 #endif
 
-    for (size_t i = 0; i < priv->left.count; i++) {
+    for (size_t i = 0; i < priv->left.count; i++)
         priv->left.mods[i] = config->left.mods[i];
-        priv->left.exps[i] = NULL;
-    }
-    for (size_t i = 0; i < priv->center.count; i++) {
+    for (size_t i = 0; i < priv->center.count; i++)
         priv->center.mods[i] = config->center.mods[i];
-        priv->center.exps[i] = NULL;
-    }
-    for (size_t i = 0; i < priv->right.count; i++) {
+    for (size_t i = 0; i < priv->right.count; i++)
         priv->right.mods[i] = config->right.mods[i];
-        priv->right.exps[i] = NULL;
-    }
 
-    struct bar *bar = malloc(sizeof(*bar));
+    struct bar *bar = calloc(1, sizeof(*bar));
     bar->private = priv;
     bar->run = &run;
     bar->destroy = &destroy;
diff --git a/decorations/background.c b/decorations/background.c
index 992bdf2..ef7b12b 100644
--- a/decorations/background.c
+++ b/decorations/background.c
@@ -30,10 +30,10 @@ expose(const struct deco *deco, cairo_t *cr, int x, int y, int width, int height
 static struct deco *
 background_new(struct rgba color)
 {
-    struct private *priv = malloc(sizeof(*priv));
+    struct private *priv = calloc(1, sizeof(*priv));
     priv->color = color;
 
-    struct deco *deco = malloc(sizeof(*deco));
+    struct deco *deco = calloc(1, sizeof(*deco));
     deco->private = priv;
     deco->expose = &expose;
     deco->destroy = &destroy;
diff --git a/decorations/stack.c b/decorations/stack.c
index a5662b0..3ffaab5 100644
--- a/decorations/stack.c
+++ b/decorations/stack.c
@@ -34,14 +34,14 @@ expose(const struct deco *deco, cairo_t *cr, int x, int y, int width, int height
 static struct deco *
 stack_new(struct deco *decos[], size_t count)
 {
-    struct private *priv = malloc(sizeof(*priv));
+    struct private *priv = calloc(1, sizeof(*priv));
     priv->decos = malloc(count * sizeof(priv->decos[0]));
     priv->count = count;
 
     for (size_t i = 0; i < count; i++)
         priv->decos[i] = decos[i];
 
-    struct deco *deco = malloc(sizeof(*deco));
+    struct deco *deco = calloc(1, sizeof(*deco));
     deco->private = priv;
     deco->expose = &expose;
     deco->destroy = &destroy;
diff --git a/decorations/underline.c b/decorations/underline.c
index 9c71efe..996d54a 100644
--- a/decorations/underline.c
+++ b/decorations/underline.c
@@ -31,11 +31,11 @@ expose(const struct deco *deco, cairo_t *cr, int x, int y, int width, int height
 static struct deco *
 underline_new(int size, struct rgba color)
 {
-    struct private *priv = malloc(sizeof(*priv));
+    struct private *priv = calloc(1, sizeof(*priv));
     priv->size = size;
     priv->color = color;
 
-    struct deco *deco = malloc(sizeof(*deco));
+    struct deco *deco = calloc(1, sizeof(*deco));
     deco->private = priv;
     deco->expose = &expose;
     deco->destroy = &destroy;
diff --git a/module.c b/module.c
index bf4ec3e..1e80c32 100644
--- a/module.c
+++ b/module.c
@@ -6,17 +6,9 @@
 struct module *
 module_common_new(void)
 {
-    struct module *mod = malloc(sizeof(*mod));
-    mod->bar = NULL;
+    struct module *mod = calloc(1, sizeof(*mod));
     mtx_init(&mod->lock, mtx_plain);
-    mod->private = NULL;
     mod->destroy = &module_default_destroy;
-
-    /* No defaults for these; must be provided by implementation */
-    mod->run = NULL;
-    mod->content = NULL;
-    mod->refresh_in = NULL;
-
     return mod;
 }
 
diff --git a/modules/alsa.c b/modules/alsa.c
index 0cb5e41..bc17a88 100644
--- a/modules/alsa.c
+++ b/modules/alsa.c
@@ -269,13 +269,10 @@ err:
 static struct module *
 alsa_new(const char *card, const char *mixer, struct particle *label)
 {
-    struct private *priv = malloc(sizeof(*priv));
+    struct private *priv = calloc(1, sizeof(*priv));
     priv->label = label;
     priv->card = strdup(card);
     priv->mixer = strdup(mixer);
-    memset(&priv->channels, 0, sizeof(priv->channels));
-    priv->vol_cur = priv->vol_min = priv->vol_max = 0;
-    priv->muted = true;
 
     struct module *mod = module_common_new();
     mod->private = priv;
diff --git a/modules/backlight.c b/modules/backlight.c
index 69cb8f5..98142f6 100644
--- a/modules/backlight.c
+++ b/modules/backlight.c
@@ -206,11 +206,9 @@ run(struct module *mod)
 static struct module *
 backlight_new(const char *device, struct particle *label)
 {
-    struct private *m = malloc(sizeof(*m));
+    struct private *m = calloc(1, sizeof(*m));
     m->label = label;
     m->device = strdup(device);
-    m->max_brightness = 0;
-    m->current_brightness = 0;
 
     struct module *mod = module_common_new();
     mod->private = m;
diff --git a/modules/battery.c b/modules/battery.c
index 2192bb0..246cc61 100644
--- a/modules/battery.c
+++ b/modules/battery.c
@@ -327,20 +327,11 @@ out:
 static struct module *
 battery_new(const char *battery, struct particle *label, int poll_interval_secs)
 {
-    struct private *m = malloc(sizeof(*m));
+    struct private *m = calloc(1, sizeof(*m));
     m->label = label;
     m->poll_interval = poll_interval_secs;
     m->battery = strdup(battery);
-
-    m->manufacturer = NULL;
-    m->model = NULL;
-
-    m->energy_full_design = 0;
-    m->energy_full = 0;
     m->state = STATE_DISCHARGING;
-    m->capacity = 0;
-    m->energy = 0;
-    m->power = 0;
 
     struct module *mod = module_common_new();
     mod->private = m;
diff --git a/modules/clock.c b/modules/clock.c
index 27e19fd..fb28633 100644
--- a/modules/clock.c
+++ b/modules/clock.c
@@ -82,7 +82,7 @@ run(struct module *mod)
 static struct module *
 clock_new(struct particle *label, const char *date_format, const char *time_format)
 {
-    struct private *m = malloc(sizeof(*m));
+    struct private *m = calloc(1, sizeof(*m));
     m->label = label;
     m->date_format = strdup(date_format);
     m->time_format = strdup(time_format);
diff --git a/modules/i3.c b/modules/i3.c
index b4951a2..7869693 100644
--- a/modules/i3.c
+++ b/modules/i3.c
@@ -248,7 +248,7 @@ handle_get_workspaces_reply(struct private *m, const struct json_object *json)
 
     size_t count = json_object_array_length(json);
     m->workspaces.count = count;
-    m->workspaces.v = malloc(count * sizeof(m->workspaces.v[0]));
+    m->workspaces.v = calloc(count, sizeof(m->workspaces.v[0]));
 
     for (size_t i = 0; i < count; i++) {
         if (!workspace_from_json(
@@ -709,7 +709,7 @@ static struct module *
 i3_new(struct i3_workspaces workspaces[], size_t workspace_count,
        int left_spacing, int right_spacing)
 {
-    struct private *m = malloc(sizeof(*m));
+    struct private *m = calloc(1, sizeof(*m));
 
     m->left_spacing = left_spacing;
     m->right_spacing = right_spacing;
@@ -722,9 +722,6 @@ i3_new(struct i3_workspaces workspaces[], size_t workspace_count,
         m->ws_content.v[i].content = workspaces[i].content;
     }
 
-    m->workspaces.v = NULL;
-    m->workspaces.count = 0;
-
     struct module *mod = module_common_new();
     mod->private = m;
     mod->run = &run;
diff --git a/modules/label.c b/modules/label.c
index 8427050..099d22f 100644
--- a/modules/label.c
+++ b/modules/label.c
@@ -37,7 +37,7 @@ run(struct module *mod)
 static struct module *
 label_new(struct particle *label)
 {
-    struct private *m = malloc(sizeof(*m));
+    struct private *m = calloc(1, sizeof(*m));
     m->label = label;
 
     struct module *mod = module_common_new();
diff --git a/modules/mpd.c b/modules/mpd.c
index b91c057..43420e6 100644
--- a/modules/mpd.c
+++ b/modules/mpd.c
@@ -565,20 +565,11 @@ refresh_in(struct module *mod, long milli_seconds)
 static struct module *
 mpd_new(const char *host, uint16_t port, struct particle *label)
 {
-    struct private *priv = malloc(sizeof(*priv));
+    struct private *priv = calloc(1, sizeof(*priv));
     priv->host = strdup(host);
     priv->port = port;
     priv->label = label;
-    priv->conn = NULL;
     priv->state = STATE_OFFLINE;
-    priv->repeat = priv->random = priv->consume = false;
-    priv->album = NULL;
-    priv->artist = NULL;
-    priv->title = NULL;
-    priv->elapsed.value = 0;
-    priv->elapsed.when.tv_sec = priv->elapsed.when.tv_nsec = 0;
-    priv->duration = 0;
-    priv->refresh_thread_id = 0;
     priv->refresh_abort_fd = -1;
 
     struct module *mod = module_common_new();
diff --git a/modules/network.c b/modules/network.c
index 2c6522f..2bc624d 100644
--- a/modules/network.c
+++ b/modules/network.c
@@ -511,17 +511,14 @@ run(struct module *mod)
 static struct module *
 network_new(const char *iface, struct particle *label)
 {
-    struct private *priv = malloc(sizeof(*priv));
+    struct private *priv = calloc(1, sizeof(*priv));
     priv->iface = strdup(iface);
     priv->label = label;
 
     priv->nl_sock = -1;
     priv->get_addresses = true;
     priv->ifindex = -1;
-    memset(priv->mac, 0, sizeof(priv->mac));
-    priv->carrier = false;
     priv->state = IF_OPER_DOWN;
-    memset(&priv->addrs, 0, sizeof(priv->addrs));
 
     struct module *mod = module_common_new();
     mod->private = priv;
diff --git a/modules/removables.c b/modules/removables.c
index e05db7d..d31c69c 100644
--- a/modules/removables.c
+++ b/modules/removables.c
@@ -545,11 +545,10 @@ run(struct module *mod)
 static struct module *
 removables_new(struct particle *label, int left_spacing, int right_spacing)
 {
-    struct private *priv = malloc(sizeof(*priv));
+    struct private *priv = calloc(1, sizeof(*priv));
     priv->label = label;
     priv->left_spacing = left_spacing;
     priv->right_spacing = right_spacing;
-    memset(&priv->devices, 0, sizeof(priv->devices));
 
     struct module *mod = module_common_new();
     mod->private = priv;
diff --git a/modules/xkb.c b/modules/xkb.c
index ae86c38..627f422 100644
--- a/modules/xkb.c
+++ b/modules/xkb.c
@@ -642,16 +642,8 @@ run(struct module *mod)
 static struct module *
 xkb_new(struct particle *label)
 {
-    struct private *m = malloc(sizeof(*m));
+    struct private *m = calloc(1, sizeof(*m));
     m->label = label;
-    m->current = 0;
-    m->layouts.count = 0;
-    m->layouts.layouts = NULL;
-    m->indicators.count = 0;
-    m->indicators.names = NULL;
-    m->caps_lock = false;
-    m->num_lock = false;
-    m->scroll_lock = false;
 
     struct module *mod = module_common_new();
     mod->private = m;
diff --git a/particle.c b/particle.c
index dfca044..5f605ea 100644
--- a/particle.c
+++ b/particle.c
@@ -28,7 +28,7 @@ particle_common_new(int left_margin, int right_margin,
                     struct font *font, struct rgba foreground,
                     struct deco *deco)
 {
-    struct particle *p = malloc(sizeof(*p));
+    struct particle *p = calloc(1, sizeof(*p));
     p->left_margin = left_margin;
     p->right_margin = right_margin;
     p->on_click_template =
@@ -120,14 +120,10 @@ exposable_default_on_mouse(struct exposable *exposable, struct bar *bar,
 struct exposable *
 exposable_common_new(const struct particle *particle, const char *on_click)
 {
-    struct exposable *exposable = malloc(sizeof(*exposable));
+    struct exposable *exposable = calloc(1, sizeof(*exposable));
     exposable->particle = particle;
-    exposable->private = NULL;
-    exposable->width = 0;
     exposable->on_click = on_click != NULL ? strdup(on_click) : NULL;
     exposable->destroy = &exposable_default_destroy;
     exposable->on_mouse = &exposable_default_on_mouse;
-    exposable->begin_expose = NULL;
-    exposable->expose = NULL;
     return exposable;
 }
diff --git a/particles/dynlist.c b/particles/dynlist.c
index ed656fc..e6a3636 100644
--- a/particles/dynlist.c
+++ b/particles/dynlist.c
@@ -98,10 +98,10 @@ struct exposable *
 dynlist_exposable_new(struct exposable **exposables, size_t count,
                       int left_spacing, int right_spacing)
 {
-    struct private *e = malloc(sizeof(*e));
+    struct private *e = calloc(1, sizeof(*e));
     e->count = count;
     e->exposables = malloc(count * sizeof(e->exposables[0]));
-    e->widths = malloc(count * sizeof(e->widths[0]));
+    e->widths = calloc(count, sizeof(e->widths[0]));
     e->left_spacing = left_spacing;
     e->right_spacing = right_spacing;
 
diff --git a/particles/list.c b/particles/list.c
index 68b7186..a47c468 100644
--- a/particles/list.c
+++ b/particles/list.c
@@ -108,9 +108,9 @@ instantiate(const struct particle *particle, const struct tag_set *tags)
 {
     const struct private *p = particle->private;
 
-    struct eprivate *e = malloc(sizeof(*e));
+    struct eprivate *e = calloc(1, sizeof(*e));
     e->exposables = malloc(p->count * sizeof(*e->exposables));
-    e->widths = malloc(p->count * sizeof(*e->widths));
+    e->widths = calloc(p->count, sizeof(*e->widths));
     e->count = p->count;
     e->left_spacing = p->left_spacing;
     e->right_spacing = p->right_spacing;
@@ -149,7 +149,7 @@ particle_list_new(struct particle *common,
                   struct particle *particles[], size_t count,
                   int left_spacing, int right_spacing)
 {
-    struct private *p = malloc(sizeof(*p));
+    struct private *p = calloc(1, sizeof(*p));
     p->particles = malloc(count * sizeof(p->particles[0]));
     p->count = count;
     p->left_spacing = left_spacing;
diff --git a/particles/map.c b/particles/map.c
index 5acc7f9..a8895cb 100644
--- a/particles/map.c
+++ b/particles/map.c
@@ -111,7 +111,7 @@ instantiate(const struct particle *particle, const struct tag_set *tags)
         pp = p->default_particle;
     }
 
-    struct eprivate *e = malloc(sizeof(*e));
+    struct eprivate *e = calloc(1, sizeof(*e));
     e->exposable = pp->instantiate(pp, tags);
 
     char *on_click = tags_expand_template(particle->on_click_template, tags);
@@ -151,7 +151,7 @@ map_new(struct particle *common, const char *tag,
         const struct particle_map particle_map[], size_t count,
         struct particle *default_particle)
 {
-    struct private *priv = malloc(sizeof(*priv));
+    struct private *priv = calloc(1, sizeof(*priv));
     priv->tag = strdup(tag);
     priv->default_particle = default_particle;
     priv->count = count;
diff --git a/particles/progress-bar.c b/particles/progress-bar.c
index a10f9e2..762178e 100644
--- a/particles/progress-bar.c
+++ b/particles/progress-bar.c
@@ -144,7 +144,7 @@ instantiate(const struct particle *particle, const struct tag_set *tags)
     long fill_count = max == min ? 0 : p->width * value / (max - min);
     long empty_count = p->width - fill_count;
 
-    struct eprivate *epriv = malloc(sizeof(*epriv));
+    struct eprivate *epriv = calloc(1, sizeof(*epriv));
     epriv->count = (
         1 +             /* Start marker */
         fill_count +    /* Before current position */
@@ -214,7 +214,7 @@ progress_bar_new(struct particle *common, const char *tag, int width,
                  struct particle *fill, struct particle *empty,
                  struct particle *indicator)
 {
-    struct private *priv = malloc(sizeof(*priv));
+    struct private *priv = calloc(1, sizeof(*priv));
     priv->tag = strdup(tag);
     priv->width = width;
     priv->start_marker = start_marker;
diff --git a/particles/ramp.c b/particles/ramp.c
index a9cf627..1f8ef11 100644
--- a/particles/ramp.c
+++ b/particles/ramp.c
@@ -120,7 +120,7 @@ instantiate(const struct particle *particle, const struct tag_set *tags)
 
     struct particle *pp = p->particles[idx];
 
-    struct eprivate *e = malloc(sizeof(*e));
+    struct eprivate *e = calloc(1, sizeof(*e));
     e->exposable = pp->instantiate(pp, tags);
 
     char *on_click = tags_expand_template(particle->on_click_template, tags);
@@ -140,9 +140,9 @@ ramp_new(struct particle *common, const char *tag,
          struct particle *particles[], size_t count)
 {
 
-    struct private *priv = malloc(sizeof(*priv));
+    struct private *priv = calloc(1, sizeof(*priv));
     priv->tag = strdup(tag);
-    priv->particles = calloc(count, sizeof(priv->particles[0]));
+    priv->particles = malloc(count * sizeof(priv->particles[0]));
     priv->count = count;
 
     for (size_t i = 0; i < count; i++)
diff --git a/particles/string.c b/particles/string.c
index 5c06378..58e1984 100644
--- a/particles/string.c
+++ b/particles/string.c
@@ -108,12 +108,9 @@ static struct exposable *
 instantiate(const struct particle *particle, const struct tag_set *tags)
 {
     const struct private *p = particle->private;
-    struct eprivate *e = malloc(sizeof(*e));
+    struct eprivate *e = calloc(1, sizeof(*e));
 
     e->text = tags_expand_template(p->text, tags);
-    memset(&e->extents, 0, sizeof(e->extents));
-    e->glyphs = NULL;
-    e->clusters = NULL;
     e->num_glyphs = -1;
     e->num_clusters = -1;
 
@@ -164,7 +161,7 @@ particle_destroy(struct particle *particle)
 static struct particle *
 string_new(struct particle *common, const char *text, size_t max_len)
 {
-    struct private *p = malloc(sizeof(*p));
+    struct private *p = calloc(1, sizeof(*p));
     p->text = strdup(text);
     p->max_len = max_len;